The inland ice of Greenland—The mountain rampart and its portals—The marginal rock islands—Rock fragments which travel with the ice—The grinding mill beneath the ice—The lifting of the grinding tools and their incorporation within the ice—Melting upon the glacier margins in Greenland—The marginal moraines—The outwash plain or apron—The continental glacier of Antarctica—Nourishment of continental glaciers—The glacier broom—Field and pack ice—The drift of the pack—The Antarctic shelf ice—Icebergs and snowbergs and the manner of their birth—Reading references 271 CHAPTER XXII THE CONTINENTAL GLACIERS OF THE “ICE AGE” Earlier cycles of glaciation—Contrast of the glaciated and nonglaciated regions—The “driftless area”—Characteristics of the glaciated regions—The glacier gravings—Younger records over older: the glacier palimpsest—The dispersion of the drift—The diamonds of the drift—Tabulated comparison of the glaciated and nonglaciated regions—Unassorted and assorted drift—Features into which the drift is molded—Marginal or “kettle” moraines—Outwash plains—Pitted plains and interlobate moraines—Eskers—Drumlins—The shelf ice of the ice age—Character profiles 297 CHAPTER XXIII GLACIAL LAKES WHICH MARKED THE DECLINE OF THE LAST ICE AGE Interference of glaciers with drainage—Temporary lakes due to ice blocking—The “parallel roads” of the Scottish glens—The glacial Lake Agassiz—Episodes of the glacial lake history within the St. Lawrence Valley—The crescentic lakes of the earlier stages—The early Lake Maumee—The later Lake Maumee—Lakes Arkona and Whittlesey—Lake Warren—Lakes Iroquois and Algonquin—The Nipissing Great Lakes—Summary of lake stages—Permanent changes of drainage effected by the glacier—Glacial Lake Ojibway in the Hudson’s Bay drainage basin—Reading references 320 CHAPTER XXIV THE UPTILT OF THE LAND AT THE CLOSE OF THE ICE AGE The response of the earth’s shell to its ice mantle—The abandoned strands as they appear to-day—The records of uplift about Mackinac Island—The present inclinations of the uplifted strands—The hinge lines of uptilt—Future consequences of the continued uptilt within the lake region—Gilbert’s prophecy of a future outlet of the Great Lakes to the Mississippi—Geological evidences of continued uplift—Drowning of southwestern shores of Lakes Superior and Erie—Reading references 340 CHAPTER XXV NIAGARA FALLS A CLOCK OF RECENT GEOLOGICAL TIME